Olefin-based polymer
AssigneeIdemitsu Petrochemical Co., Ltd.
InventorsTomio Tatsumi, Shuji Machida, Mitsugu Kanzawa, Yutaka Minami, Yasuhiro Goto, Masato Kijima
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Abstract
Long-chain, branched, propylene-based polymers, of which the melt index and the molecular weight distribution and the melt tension and the limiting viscosity both satisfy specific requirements, have good physical properties that are comparable to or better than those of conventional propylene-based polymers. They have good melt workability and are favorable to large-size blow molding and extrusion foaming. They are favorably used as miscibility improvers for propylene homopolymers and propylene-based copolymers.
Claims16
A propylene-based polymer characterized in that (a) the ratio of MI5/MI2.16, MI5 being the melt index of the polymer (g/10 min) as measured at a temperature of 230° C. and under a load of 5.0 kg, and MI2.16 being the melt index thereof (g/10 min) as measured at the same temperature but under a load of 2.16 kg, and the ratio of Mw/Mn, Mw being the weight-average molecular weight of the polymer and Mn being the number-average molecular weight thereof both measured through gel permeation chromatography, satisfy the following requirement:
- MI5/MI2.16≧0.240×Mw/Mn+3.1 (I),
- that (b) the melt tension, MS (g), of the polymer as measured at a temperature of 230° C., and the limiting viscosity [h] (dl/g) thereof as measured in a solvent of tetracycline at a temperature of 135° C. satisfy the following requirement:
- log MS≧3.17×log[h]−0.68 (II),
- and that said limiting viscosity [h] falls between 0.1 and 15.0 dl/g.
A branched polyolefin having a main chain of a polymer of at least one or more monomers selected from ethylene, a-olefins having from 4 to 20 carbon atoms, cyclic olefins and styrenes, and side chains of a propylene homopolymer or a copolymer of propylene with at least one or more monomers selected from ethylene, a-olefins having from 4 to 20 carbon atoms, cyclic olefins and styrenes, wherein the side chains have an isotactic triad fraction [mm] of not smaller than 80%, said fraction indicating the stereospecificity of the propylene-bonding site in the side chains.
A branched polyolefin having a main chain of a polymer of at least one or more monomers selected from a-olefins having from 2 to 20 carbon atoms, cyclic olefins and styrenes, and side chains of a copolymer of propylene with at least one or more monomers selected from ethylene, a-olefins having from 4 to 20 carbon atoms, cyclic olefins and styrenes, wherein the side chains have an isotactic triad fraction [mm] of not smaller than 80%, said fraction indicating the stereospecificity of the propylene-bonding site in the side chains.
A branched polyolefin characterized in that (a) its propylene content falls between 60 and 99.9% by weight, that (b) the ratio of MI5/MI2.16, MI5 being the melt index of the polymer (g/10 min) as measured at a temperature of 230° C. and under a load of 5.0 kg, and MI2.16 being the melt index thereof (g/10 min) as measured at the same temperature but under a load of 2.16 kg, and the ratio of Mw/Mn, Mw being the weight-average molecular weight of the polymer and Mn being the number-average molecular weight thereof both measured through gel permeation chromatography, satisfy the following requirement:
- MI5/MI2.16≧0.240×Mw/Mn+3.10 (I),
- that (c) its melt tension, MS (g), and its melt index, MI (g/10 min), both measured at a temperature of 230° C. satisfy the following requirement:
- log MS>−0.907×log MI+0.375 (II),
- that its limiting viscosity [h] as measured in a solvent of tetracycline at a temperature of 135° C. falls between 0.1 and 15.0 dl/g, and that it has a main chain of a polymer (except propylene homopolymers) of at least one or more monomers selected from a-olefins having from 2 to 20 carbon atoms, cyclic olefins and styrenes, and graft chains of a copolymer of ethylene with one or more monomers selected from a-olefins having from 3 to 20 carbon atoms, cyclic olefins and styrenes.
Dependencies are inferred from the claim text.